BTZS (Beyond the Zone System) is a process and book by Phil Davis. Central to BTZS is a method of performing personalized materials testing so that the photographer can get the most out his or her chosen materials and working methods. The goal is to produce easy to print B&W negatives with ease. It is a system that is suitable for both the beginning large format photographer or the expert.

ExpoDev was uniquely designed for the BTZS process, using data (Film Profiles) that is taken directly from the user’s personal materials testing. This data is produced by an application, Plotter for Windows, which is sold by TinyOctopus, LLC

More information on the BTZS process mat be found by reading Beyond the Zone System, 4th edition by Phil Davis or by visiting http://BTZS.org